Before we can determine we're going "that far", we need to first know how far we're going. So how far are we going that it is too far?
I think the difference in backgrounds is what separates your opinion of healthy from mine. I am healthy because I am in such good shape. Me looking like Brad Pitt sacking Troy is a side effect of that, but it isn't something I've gone out of my way to pursue. If your muscle mass isn't really affected by 2 hours of cardio, I imagine it isn't terribly intense, which is perfectly fine. I run pretty fast, and doing so for an hour plus caused me to start burning away my muscle. So I do more sprints than long distance running now, and I'm better off for it, as I'm still perfectly capable of running long distances. As for cutting and bulking, it isn't something I actually engage in. I eat healthy foods by default, and bulk would only serve to slow me down and affect my cardio and endurance. I'll carbload once a week just to have energy to burn, but that's about as far as that goes. Someone the size of the Hulk would not fair well in the infantry, so most steer clear of that physique. I choose lean, efficient, functional muscle over bulk, as my musculature is based on the needs of my former job, and not aesthetics.
That said, it seems like everyone is assuming I'm in the gym lifting heavy things. Newsflash: I don't like the gym, and I use a limited set of equipment. As I said before, everything you need you already have. Doing some weight lifting most definitely helps, especially since I'm never just carrying my body weight, but I can break anyone off using solely calisthenics more easily than if I were just to have someone lift heavy things, since the latter is completely stationary.